Six-speed manual transmission

ABSTRACT

In a six-speed manual transmission, a plurality of first synchronizers are disposed to an input shaft and at least one second synchronizer is disposed to an output shaft. Reflected inertia can be reduced, power delivery efficiency can be improved, and manufacturing costs can be reduced.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2005-0126875 filed in the Korean IntellectualProperty Office on Dec. 21, 2005, the entire contents of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a six-speed manual transmission. Moreparticularly, the present invention relates to a six-speed manualtransmission that can reduce reflected inertia and fuel consumption, andalso improve power performance.

(b) Description of the Related Art

Generally, a six-speed manual transmission is an apparatus for changingshift speeds by sequentially operating a control finger, a shift lug, ashift rail, and a shift fork when a driver operates a shift lever.

In prior art transmissions, because driven gears of a five-speedpowertrain of the manual transmission are often integrally formed withthe output shaft, a problem can occur in that rotational inertia of theoutput shaft can be large. Reflected inertia refers to an inertia forcereversely transmitted from another constituent element to an inputelement in a power delivery apparatus. Thus, because rotational inertiaof the output shaft can be large, a problem can occur in that thereflected inertia can be large when gears are shifted. In addition,because the weight of the output shaft can be large, problem can occurin that power delivery efficiency is reduced and costs increased.

In prior proposed solutions, the reflected inertia may be reduced bydisposing the fifth forward speed drive gear to the output shaft,however, in this case a problem can occur in that costs are increasedbecause an additional synchronizer has to be mounted. As a result priorproposed solutions are less then satisfactory.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the invention andtherefore it may contain information that does not form the prior artthat is already known in this country to a person of ordinary skill inthe art.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a six-speed manualtransmission having advantages of reducing a reflected inertia andmanufacturing costs, and also of improving a power performance.

An exemplary embodiment of the present invention provides a six-speedmanual transmission variably transmitting a power including: an inputshaft; a plurality of first drive gears selectively engaged to the inputshaft such that the first gears selectively transmit the power shiftedby predetermined speed ratios; at least one second drive gear integrallyformed with the input shaft and transmitting the power of the inputshaft; an output shaft receiving the power from the input shaft throughthe first and second drive gears; a plurality of first driven gearsintegrally formed with the output shaft and corresponding to the firstdrive gears; and at least one second driven gear selectively engaged tothe output shaft to selectively receive the power shifted by thepredetermined speed ratios.

The six-speed manual transmission further includes: a plurality of firstsynchronizers disposed to the input shaft and synchronizing rotationspeeds of the first drive gear engaged to the input shaft and the outputshaft in a case that one of the first drive gears is engaged to theinput shaft to selectively receive the power; and at least one secondsynchronizer disposed to the output shaft and synchronizing rotationspeeds of the second driven gear engaged to the output shaft and theinput shaft in a case that the at least one second driven gear isengaged to the output shaft to selectively receive the power.

A bearing supporting the output shaft is mounted to one side of theoutput shaft and is realized by a needle roller bearing.

The first drive gears are disposed in an order of a fifth forward speedgear, a sixth forward speed gear, a second shift speed gear, a firstforward speed gear, and a reverse speed gear from a front of the inputshaft.

The second driven gears are disposed in an order of a fourth forwardspeed gear and a third forward speed gear from a front of the outputshaft.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a six-speed manual transmission according to an exemplaryembodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

An exemplary embodiment of the present invention will hereinafter bedescribed in detail with reference to the accompanying drawings.

As shown in FIG. 1, according to an exemplary embodiment of the presentinvention, a six-speed manual transmission includes an input shaft 201,a plurality of first drive gears 213, at least one second drive gear220, an output shaft 221, a plurality of first driven gears 260, and atleast one second driven gear 270. A housing surrounding and supportingthese components, as would be understood by a person of ordinary skillin the art, is not shown.

The plurality of first drive gears 213 are selectively engaged to theinput shaft 201 to selectively transmit a power shifted by predeterminedspeed ratios.

At least one second drive gear 220 is disposed on the input shaft 201.The output shaft 221, transmitting the power of the input shaft 201,receives the power from the input shaft 201 through first and seconddrive gears 213 and 220. At least one first driven gear 260 is disposedon the output shaft 221 and cooperates with the first drive gears 213.The drive gears and driven gears may be integrally formed with theirrespective shafts.

At least one second driven gear 270 is selectively engaged to the outputshaft 221 to selectively receive the power shifted by the predeterminedspeed ratios. If the power is input from an engine (not shown) to theinput shaft 201, the input shaft 201 rotates, and so the second drivegear 220 integrally formed with the input shaft 201 rotates with theinput shaft 201. The power input to the input shaft 201 is transmittedto the driven shaft 221 through the first drive gears 213 and the seconddrive gear 220.

According to an exemplary embodiment of the present invention, thesix-speed manual transmission includes a plurality of firstsynchronizers 240 and at least one second synchronizer 243. Theplurality of first synchronizers 240 are disposed to cooperate with theinput shaft 201. The first drive gears 213 are always engaged to thefirst driven gears 260 and only disposed to the input shaft 201. Inaddition, bearings are disposed between the first drive gears 213 andthe input shaft. Therefore, the first drive gears 213 are slidablydisposed on the input shaft 201. The power is transmitted through theinput shaft 201, the first synchronizers 240, and the first driven gears260 sequentially. That is, the first drive gears are engaged to theinput shaft 201 through the first synchronizers 240.

The at least one second synchronizer 243 is disposed to cooperate withthe output shaft 221 and synchronize rotation speed of the second drivengear 270 in a case that at least one second driven gear 270 is engagedbetween the input shaft 201 to the output shaft 221 to selectivelyreceive the power.

When a driver operates a shift lever (not shown), a control finger, ashift lug, and a shift fork (not shown) are sequentially operated and ashift speed is realized by operation of the first and secondsynchronizers 240 and 243.

In one embodiment, the plurality of first drive gears 213 may include afifth forward speed drive gear 203, a sixth forward speed drive gear205, a second forward speed drive gear 207, a first forward speed drivegear 209, and a reverse speed drive gear 211, and the fifth forwardspeed drive gear 203, the sixth forward speed drive gear 205, the secondforward speed drive gear 207, the first forward speed drive gear 209,and the reverse speed drive gear 211 are sequentially disposed from afront of the input shaft 201.

The at least one second drive gear 220 may include a fourth forwardspeed drive gear 215 and a third forward speed drive gear 217.

The plurality of first driven gears 260 may include a fifth forwardspeed driven gear 223, a sixth forward speed driven gear 225, a secondforward speed driven gear 227, a first forward speed driven gear 229,and a reverse speed driven gear 231, and the at least one second drivengear 270 includes a fourth forward speed driven gear 233 and a thirdforward speed driven gear 235.

The fourth forward speed driven gear 233 and third forward speed drivengear 235 are sequentially disposed to the output shaft 221 from a frontthereof.

The plurality of first synchronizers 240 may include a fifth forwardspeed and sixth forward speed synchronizer 237, a second forward speedand first forward speed synchronizer 239, and a reverse speedsynchronizer 241, and each synchronizer 237, 239, and 241 includes twosynchronizers or one synchronizer. That is, according to an exemplaryembodiment of the present invention, the six-speed manual transmissionmay include five first synchronizers 240.

Each shift fork may be engaged to each first synchronizer 240.

That is, referring to FIG. 1, if the fifth forward speed and sixthforward speed synchronizer 237 moves left, a fifth forward speedshifting is realized, and if it moves right, a sixth forward speedshifting is realized. Similarly, if the second forward speed and firstforward speed synchronizer 239 moves left, a second forward speedshifting is realized, and if it moves right, a first forward speedshifting is realized. In addition, if the reverse speed synchronizer 241moves left, a reverse speed shifting is realized.

According to an exemplary embodiment of the present invention, a secondsynchronizer 243 may include a fourth forward speed and third forwardspeed synchronizer 243 and is disposed to the output shaft 221. That is,because only the fourth forward speed and third forward speedsynchronizer 243 is disposed on the output shaft 221, the weight of theoutput shaft 221 becomes light and the rotational inertia amount, thereflected inertia, and manufacturing costs of the output shaft 221 canbe reduced. Therefore, power delivery efficiency of the output shaft 221can be improved. By way of illustration, according to an experimentedresult, the described rotational inertia amount is reduced by about 20%.

According to a further exemplary embodiment of the present invention,because a scheme of the six-speed transmission is not more complex thana fifth speed manual transmission of the prior art, manufacturingprocesses of the six-speed transmission is simplified. In addition,according to an exemplary embodiment of the present invention, becausesixth forward speeds can be realized, climbing performance and a highestspeed of the vehicle can be improved.

In one embodiment, the fourth forward speed and third forward speedsynchronizer 243 may include two synchronizers, and if the fourthforward speed and third forward speed synchronizer 243 moves left, afourth forward speed shifting is realized, and if it moves right, athird forward speed shifting is realized. In addition, according to anexemplary embodiment of the present invention, because the fourthforward speed and third forward speed synchronizer 243 is disposed tothe output shaft 221, one shift fork is located to the fourth forwardspeed and the third forward speed synchronizer 243.

The shift fork may be arranged by a person of an ordinary skill in theart, based on the teachings contained herein and as such furtherdetailed description of the shift fork is omitted.

Because the second drive gear 220 rotates with the input shaft 201, ifthe fourth forward speed and third forward speed synchronizer 243 movesleft, the rotation speeds of the input shaft 201 and the output shaft221 are synchronized and the power is transmitted from the fourthforward speed drive gear 215 to the fourth forward speed driven gear233. In addition, if the fourth forward speed and third forward speedsynchronizer 243 move right, the rotation speeds of the input shaft 201and the output shaft 221 are synchronized and the power is transmittedfrom the third forward speed drive gear 217 to the third forward speeddriven gear 235.

Power delivery from the first drive gears 213 to the first driven gears260 will be understood by a person of an ordinary skill in the art basedon the teachings contained herein, therefore further detaileddescription is omitted herein.

A bearing 250 supporting the output shaft 221 may be mounted to one sideof the output shaft 221 and the bearing 250. In one embodiment bearing250 may be a needle roller bearing. A needle roller bearing 250 has asmall volume and weight and therefore the weight of the output shaft 221can be further reduced. Therefore, the rotational inertia, the reflectedinertia, and the manufacturing costs of the output shaft 221 can also befurther reduced.

According to exemplary embodiments of the present invention, because thesynchronizer is disposed to the output shaft, the rotational inertia,the reflected inertia, and the manufacturing costs of the output shaftcan be reduced.

In addition, power delivery efficiency of the manual transmission can beimproved and because the sixth forward speed shift can be realized,climbing performance and highest speed of the vehicle can be improved.

While this invention has been described in connection with what ispresently considered to be practical exemplary embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

1. A six-speed manual transmission comprising: an input shaft; aplurality of first drive gears selectively engaged to the input shaftsuch that the first gears selectively transmit power shifted bypredetermined speed ratios; at least one second drive gear disposed onthe input shaft and transmitting power of the input shaft; an outputshaft receiving the power from the input shaft through the first andsecond drive gears; a plurality of first driven gears disposed on theoutput shaft and corresponding to the first drive gears; and at leastone second driven gear selectively engaged to the output shaft toselectively receive power shifted by the predetermined speed ratios. 2.The transmission of claim 1, further comprising: a plurality of firstsynchronizers disposed to cooperate with the input shaft andsynchronizing rotation speeds of the first drive gear engaged to theinput shaft and the output shaft in a case that one of the first drivegears is engaged to the input shaft to selectively receive the power;and at least one second synchronizer disposed to cooperate with theoutput shaft and synchronizing rotation speeds of the second driven gearengaged to the output shaft and the input shaft in a case that the atleast one second driven gear is engaged to the output shaft toselectively receive the power.
 3. The transmission of claim 1, wherein:a bearing supporting the output shaft is mounted to one side of theoutput shaft.
 4. The transmission of claim 3, wherein the bearing is aneedle bearing.
 5. The transmission of claim 1, wherein: the first drivegears are disposed in an order of a fifth forward speed gear, a sixthforward speed gear, a second shift speed gear, a first forward speedgear, and a reverse speed gear from a front of the input shaft.
 6. Thetransmission of claim 1, wherein: the second driven gears are disposedin an order of a fourth forward speed gear and a third forward speedgear from a front of the output shaft.
 7. The transmission of claim 1,wherein said at least one second drive gear is integrally formed withthe input shaft.
 8. The transmission of claim 1, wherein at least onesaid first driven gear is integrally formed with said output shaft.